Nitrile removal process and etherification process with same

ABSTRACT

This invention provides a process to remove nitriles. This invention also provides an improved etherification process that reduces the amount of acidic-ion-exchange-resin catalyst that is deactivated by nitriles. These processes use a water phase to remove nitriles from a hydrocarbon phase followed by a steam, or fuel gas, phase to remove the nitriles from the water phase.

BACKGROUND

This invention relates to nitrile removal. This invention also relatesto the production of compounds comprising ether linkages (--C--O--C--).In particular, this invention relates to the production ofalkyl-tertiary-alkyl ethers.

Alkyl-tertiary-alkyl ethers are useful as octane improvers for liquidfuels, such as, for example, gasoline. Also, because of the low vaporpressure of alkyl-tertiary-alkyl ethers, they are particularly usefulfor reducing the vapor pressure of gasoline.

Federal government regulations require that some gasolines containgreater concentration levels of oxygen-containing compounds.Alkyl-tertiary-alkyl ethers have been found to be especially suitablefor assisting in the compliance with these Federal regulations.

While processes for the production of alkyl-tertiary-alkyl ethers areknown in the art, not all problems associated with such processes havebeen solved. For example, refinery-catalytic-cracker-hydrocarbonstreams, which are typically used for the production ofalkyl-tertiary-alkyl ethers, contain undesirable compounds, such as, forexample, nitriles. Specific examples of these nitriles are acetonitrile(CH₃ CN also known as methyl cyanide) and propionitrile (C₂ H₅ CN alsoknown as ethyl cyanide). These nitriles are undesirable because they canpoison an acidic-ion-exchange-resin catalyst being used in anetherification process. At levels as low as about 15 to about 30 partsper million by weight based on the total weight of a feed stream to anetherification reactor, a typical acidic-ion-exchange-resin-catalyst bedcould be deactivated in as little as three months. Replacement of anacidic-ion-exchange-resin-catalyst bed could cost from about 100,000 toabout 200,000 U.S. Dollars for a typical fixed-bed reactor to as high as1,000,000 U.S. Dollars for a complex catalytic-distillation reactor.Consequently, a more efficient etherification process that reduces theamount of acidic-ion-exchange-resin catalyst that is deactivated by suchnitriles would be of great value both economically and technologically.

SUMMARY

It is an object of this invention to provide a nitrile removal process.

It is another object of this invention to provide an improvedetherification process that resists deactivation, by nitriles, of itsacidic-ion-exchange-resin catalyst.

In accordance with this invention a nitrile removal process is provided.This process comprises (or optionally consists essentially of):

(a) contacting a First Isoolefin Stream, which comprises isoolefins,nitriles, and nonreactive compounds, with a First Water Stream, whichcomprises water, in a first contacting means under conditions thatproduce a Second Isoolefin Stream and a Second Water Stream from saidFirst Isoolefin Stream and said First Water Stream, where said SecondIsoolefin Stream comprises said isoolefins and said nonreactivecompounds, and where said Second Water Stream comprises said water andsaid nitriles, and where said Second Isoolefin Stream is lean in saidnitriles when compared with said First Isoolefin Stream, and where saidSecond Water Stream is rich in said nitriles when compared with saidFirst Water Stream;

(b) contacting said Second Water Stream with a First Steam Stream, or aFirst Fuel Gas Stream, in a contacting zone under conditions thatproduce a First Nitrile Steam, from said Second Water Stream and saidFirst Steam Stream, or said First Fuel Gas Stream, where said FirstNitrile Stream comprises said nitriles.

In accordance with this invention, an improved etherification processthat resists deactivation, by nitriles, of its acidic-ion-exchange-resincatalyst, is provided. This process comprises (or optionally consistsessentially of):

(a) contacting a First Isoolefin Stream, which comprises isoolefins,nitriles, and nonreactive compounds, with a First Water Stream, whichcomprises water, in a first contacting means under conditions thatproduce a Second Isoolefin Stream and a Second Water Stream from saidFirst Isoolefin Stream and said First Water Stream, where said SecondIsoolefin Stream comprises said isoolefins and said nonreactivecompounds, and where said Second Water Stream comprises said water andsaid nitriles, and where said Second Isoolefin Stream is lean in saidnitriles when compared with said First Isoolefin Stream, and where saidSecond Water Stream is rich in said nitriles when compared with saidFirst Water Stream;

(b) contacting said Second Isoolefin Stream with a First Alcohol Stream,which comprises alcohols, in an Isoolefin/Alcohol contacting zone wheresaid Second Isoolefin Stream can come into contact with said FirstAlcohol Stream, to form a First Isoolefin/Alcohol Stream that comprisessaid isoolefins, said nonreactive compounds, and said alcohols;

(c) contacting said First Isoolefin/Alcohol Stream with anacidic-ion-exchange-resin catalyst, in a second contacting zone underconditions that produce a First Ether Stream from said FirstIsoolefin/Alcohol Stream, where said First Ether Stream comprisesunreacted isoolefins, unreacted alcohols, said nonreactive compounds,and ethers;

(d) separating said First Ether Stream in a first separating zone underconditions that produce a Second Isoolefin/Alcohol Stream and a SecondEther Stream from said First Ether Stream, where said SecondIsoolefin/Alcohol Stream comprises said unreacted isoolefins, saidunreacted alcohols, and said nonreactive compounds, and said SecondEther Stream comprises said ethers, and where said SecondIsoolefin/Alcohol Stream is lean in said ethers and said Second EtherStream is rich in said ethers;

(e) contacting said Second Isoolefin/Alcohol Stream with a Third WaterStream in a third contacting zone under conditions that produce a FirstAlcohol/Water Stream and a Third Isoolefin Stream from said SecondIsoolefin/Alcohol Stream and said Third Water Stream, where said ThirdIsoolefin Stream comprises said unreacted isoolefins and saidnonreactive compounds, and where said First Alcohol/Water Streamcomprises said unreacted alcohols and said water;

(f) separating said First Alcohol/Water Stream in a second separatingzone where said First Alcohol/Water Stream is separated under conditionsthat produce said Third Water Stream and said First Alcohol Stream fromsaid First Alcohol/Water Stream, where said First Alcohol Streamcomprises said unreacted alcohols, and said Third Water Stream compriseswater, and where said First Alcohol Stream is rich in said alcohols andsaid Third Water Stream is lean in said alcohols;

(g) contacting said Second Water Stream with a First Steam Stream, or aFirst Fuel Gas Stream, in a fourth contacting zone under conditions thatproduce said First Water Stream and a First Nitrile Stream, from saidSecond Water Stream and said First Steam Stream, or said First Fuel GasStream, where said First Water Stream comprises said water and saidFirst Nitrile Stream comprises said nitriles, and where said First WaterStream is lean in said nitriles and said First Nitrile Stream is rich insaid nitriles.

Other objects of this invention and their advantages will becomeapparent from the following.

BRIEF DESCRIPTION OF THE FIGURE

The FIGURE is a diagrammatic representation of a preferred embodiment ofan Etherification Structure that is useful in performing a preferredembodiment of the process of this invention. The FIGURE will bedescribed in more detail herein.

DETAILED DESCRIPTION OF THE INVENTION

Alkyl-tertiary-alkyl ethers can be produced by reacting primaryalcohols, or secondary alcohols, with isoolefin compounds, in thepresence of an acidic-ion-exchange-resin catalyst. Common etherificationreactions involve reacting methanol with various isoalkenes, such as,for example:

2-methyl-1-propene ((CH₃)₂ C:CH₂ also known as isobutylene);

2-methyl-1-butene (H₂ C:C(CH₃)CH₂ CH₃); or

2-methyl-2-butene (H₃ CCH:C(CH₃)₂ also known as β-isoamylene);

to form alkyl-tertiary-alkyl ethers.

The isoolefins useful in this invention are generally alkenes havingfrom 4 to about 16 carbon atoms per molecule. Suitable examples of theseisoolefins are isobutylene, isoamylene, isohexylene, isoheptylene,isooctylene, isononylene, isodecylene, isoundecylene, isododecylene,isotridecylene, isotetradecylene, isopentadecylene, and isohexadecylene.Mixtures of two or more of these isoolefins can also be used in thisinvention.

The alcohols useful in this invention are generally primary alcohols, orsecondary alcohols, having from 1 to about 12 carbon atoms per molecule.Suitable examples of these alcohols are methanol, ethanol, propanol,isopropanol, butanol, secondary butanol, pentanol, hexanol, ethyleneglycol, propylene glycol, butylene glycol, and glycerol. Mixtures of twoor more of these alcohols can also be used in this invention.Polyethylene glycols can also be used in this invention in place of, orin conjunction with, the above-identified types of alcohols.

Currently, the preferred isoolefins are isobutylene and the isoamylenes.This is because they can react with methanol and ethanol, which is thecurrently preferred alcohols, to produce, respectively,methyl-tertiary-butyl ether, methyl-tertiary-amyl ether, andethyl-tertiary-butyl-ether.

Any suitable molar ratio of alcohol to isoolefin can be used in thisinvention. In general, the molar ratio of alcohol to isoolefin in thefeed stream to the ether-production vessel can be in the range of about0.5:1 to about 4:1. It is preferable if said ratio is from about 0.8:1to about 1.2:1 and it is most preferable if said ratio is 1:1.

The acidic-ion-exchange-resin catalysts useful in this invention aregenerally sulfonated coals and sulfonated resins. These catalysts can beused separately or together in .the same etherification reactor.

The sulfonated coals useful in this invention are generally highmolecular weight carbonaceous materials that contain at least one SO₃ Hgroup. Suitable examples of such sulfonated coals are available underthe designations "Zeo-Karb H"™, "Nalcite X"™, and "Nalcite AX"™. Thesesulfonated coals can be obtained from various commercial sources.Sulfonated coals are generally produced by the treatment of bituminouscoals with sulfuric acid. They are often marketed as water softeners orbase exchangers. These materials are usually available in a neutralizedform and as such must be activated to the acidic form by treatment witha strong mineral acid. Usually water is then used to remove anyremaining sodium and chloride ions prior to use.

The sulfonated resins useful in this invention are generally hydrocarbonpolymers that contain at least one SO₃ H group. Sulfonated resins arepresently preferred as the acidic-ion-exchange-resin catalysts used inthis invention. Suitable examples include, but are not limited to, thereaction products of phenol formaldehyde resins with sulfuric acid.Commercial examples of these resins are available under the designations"Amberlite IR-1"™, "Amberlite IR-100"™ and "Nalcite MX"™. Also usefulare the sulfonated resinous polymers of coumarone-indene withcyclopentadiene and furfural, and sulfonated polymers of cyclopentadienewith furfural.

Currently, the most preferred acidic-ion-exchange-resin catalysts arethe sulfonated polystyrene resins. Suitable examples of these sulfonatedpolystyrene resins include, but are not limited to, a divinylbenzenecrosslinked polystyrene matrix having from about 0.5 to 20 weightpercent, preferably from about 4 to about 16 weight percent, ofcopolymerized divinylbenzene therein to which are functionable sulfonicacid groups, or groups ionizable to functional sulfonic acid groups.These resins are commercially available under the designation "Dowex50"™, "Nalcite HCR"™, and "Amberlyst 15"™. These resins whencommercially obtained have solvent contents of about 50 weight percent.This solvent can either be removed before use or the resin can be usedas-is.

The resin particle size can be any suitable size, however, particlesizes from about 10 to about 50 mesh (U.S. Sieve Series) are currentlypreferred.

The isoolefins used in this invention are usually obtained from arefinery-catalytic-cracker-hydrocarbon stream. Such streams usuallycomprise isoolefins, nitriles, and other nonreactive compounds. Thenonreactive compounds are usually hydrocarbons that do not react, orreact very slowly, when they come into contact with anacidic-ion-exchange-resin catalyst. Typical examples of such nonreactivecompounds include, but are not limited to, alkanes and straight chainolefins. The nonreactive compounds are also useful as diluents in thisinvention.

The temperature of the steam used in this invention can be in the rangeof about 100° C. to about 300° C. However, it is more preferred if thetemperature of the steam is in the range of 125° C. to 200° C. Thepressure, under which the steam is used in this invention, can be in therange of about 10 psig to about 200 psig. However, it is more preferredif the pressure is in the range of 20 psig to 100 psig.

The fuel gas used in this invention can be any composition that can beburned in a furnace for the generation of heat or used in an engine forthe generation of power. The fuel gas can be, for example, a distillatedfraction of petroleum, a residuum from refinery operations, a crudepetroleum, or a mixture of two or more of these. Typically, thetemperature of the fuel gas can be in the range of about 50° C. to about250° C. However, it is more preferred if the temperature of the fuel gasis in the range of 75° C. to 175° C. The pressure, under which the fuelis used in this invention, can be in the range of about 10 psig to about200 psig. However, it is more preferred if the pressure is in the rangeof 75 psig to 175 psig.

Additional information concerning these types of processes can be foundin U.S. Pat. No. 5,237,109 (the disclosure of which is herebyincorporated by reference).

In accordance with this invention, a First Isoolefin Stream, whichcomprises isoolefins, nitriles, and nonreactive compounds, is contactedwith a First Water Stream, which comprises water, in a first contactingmeans that provides a first contacting zone where said First IsoolefinStream can come into contact with said First Water Stream. An example ofsuch first contacting means is a wash column. This is the firstnitrile-removal stage. This contacting takes place under conditions thatproduce a Second Isoolefin Stream and a Second Water Stream from saidFirst Isoolefin Stream and said First Water Stream, where said SecondIsoolefin Stream comprises said isoolefins and said nonreactivecompounds, and where said Second Water Stream comprises said water andsaid nitriles, and where said Second Isoolefin Stream is lean in saidnitriles when compared with said First Isoolefin Stream, and where saidSecond Water Stream is rich in said nitriles when compared with saidFirst Water Stream. In general, the temperature, in said firstcontacting means, should be from about 10° C. to about 100° C. and thepressure should be from about 15 psig to about 150 psig. Currently, itis preferred if the temperature is from 20° C. to 50° C. and if thepressure is from 25 psig to 125 psig.

Said Second Isoolefin Stream is then contacted with a First AlcoholStream, which comprises alcohols, in an Isoolefin/Alcohol contactingmeans that provides an Isoolefin/Alcohol contacting zone where saidSecond Isoolefin Stream can come into contact with said First AlcoholStream, to form a First Isoolefin/Alcohol Stream that comprises saidisoolefins, said nonreactive compounds, and said alcohols: Examples ofsaid Isoolefin/Alcohol-contacting means are conduits and/or connectingends.

Said First Isoolefin/Alcohol Stream is contacted with anacidic-ion-exchange-resin catalyst, in a second contacting means thatprovides a second contacting zone where said First Isoolefin/AlcoholStream can come into contact with an acidic-ion-exchange-resin catalystand thereby produce ethers. An example of said second contacting meansis a reactor. Further information concerning reactors can be found inthe Encyclopedia of Chemical Processing and Design vol.46, pages 245-350(1994). This is the ether-production step. This contacting takes placeunder conditions that produce a First Ether Stream from said FirstIsoolefin/Alcohol Stream, where said First Ether Stream comprisesunreacted isoolefins, unreacted alcohols, said nonreactive compounds,and said ethers. In general, the temperature, inside said secondcontacting means, should be from about 0° C. to about 150° C. and thepressure should be from about 30 psig to about 300 psig. Currently, itis preferred if the temperature is from 25° C. to 75° C. and if thepressure is from 25 psig to 125 psig. Generally, these etherificationreactions are conducted with most of the reactants in the liquid phase.When such etherification reactions are performed with most of thereactants in the liquid phase, the liquid hourly space velocity (LHSV)of the feed to the etherification vessel should be from about 1/hour toabout 20/hour. Preferably the LHSV is from about 2/hour to about 10/hourand most preferably the LHSV is from 3/hour to 5/hour.

Said First Ether Stream can optionally be contacted with anotheracidic-ion-exchange-resin catalyst in a separate contacting means thatprovides a separate contacting zone where said First Ether Stream cancome into contact with an acidic-ion-exchange-resin catalyst, which canbe the same as, or different from, the acidic-ion-exchange-resincatalyst used in said second contacting means. Said separate contactingmeans can be the same as, or different from, said second contactingmeans. In general, the temperature and pressure conditions inside saidseparate contacting means can be the same as, or different from, theconditions used in said second contacting means.

Said First Ether Stream is separated in a first separating means thatprovides a first separating zone where said First Ether Stream isseparated into two streams where one stream is rich in said ethers andthe other is lean in said ethers. An example of said first separatingmeans is a fractionator. Further information concerning fractionatorscan be found in the Encyclopedia of Chemical Processing and Design vol.16, pages 42-133 (1982). This is the ether-separation step. Thisseparating takes place under conditions that produce a SecondIsoolefin/Alcohol Stream and a Second Ether Stream from said First EtherStream, where said Second Isoolefin/Alcohol Stream comprises saidunreacted isoolefins, said unreacted alcohols, and said nonreactivecompounds, and said Second Ether Stream comprises said ethers, and wheresaid Second Second Ether Stream is lean in said ethers and said SecondIsoolefin Stream is rich in said ethers. In general, the temperature,inside said first separating means, should be from about 10° C. to about250° C. and the pressure should be from about 0 psig to about 300 psig.Currently, it is preferred if the temperature is from 20° C. to 200° C.and if the pressure is from 100 psig to 200 psig.

Said Second Ether Stream exits said first separating means and enters anether-collection point.

Said Second Isoolefin/Alcohol Stream is contacted with a Third WaterStream in a third contacting means that provides a third contacting zonewhere said Second Isoolefin/Alcohol Stream can come into contact withsaid Third Water Stream. An example of said third contacting means is anextractor. Further information concerning extractors can be found in theEncyclopedia of Chemical Processing and Design vol. 16, pages 42-133(1982). This is the isoolefin/nonreactive-compound-extraction step. Thiscontacting takes place under conditions that produce a FirstAlcohol/Water Stream and a Third Isoolefin Stream from said SecondIsoolefin/Alcohol Stream and said Third Water Stream, where said ThirdIsoolefin Stream comprises said unreacted isoolefins and saidnonreactive compounds, and where said First Alcohol/Water Streamcomprises said unreacted alcohols and said water. In general, thetemperature, inside said third contacting means, should be from about10° C. to about 100° C. and the pressure should be from about 15 psig toabout 150 psig. Currently, it is preferred if the temperature is from25° C. to 65° C. and if the pressure is from 25 psig to 65 psig.

Said Third Isoolefin Stream exits said third contacting means and enterssaid nonreactive-compound-collection point.

Said First Alcohol/Water Stream is separated in a second separatingmeans that provides a second separating zone where said FirstAlcohol/Water Stream is separated into two streams where one stream isrich in said alcohols and the other is lean in said alcohols. An exampleof said second separating means is a fractionator. This is thealcohol-removal step. This contacting takes place under conditions thatproduce said Third Water Stream and said First Alcohol Stream from saidFirst Alcohol/Water Stream, where said First Alcohol Stream comprisessaid unreacted alcohols, and said Third Water Stream comprises water,and where said First Alcohol Stream is rich in said alcohols and saidThird Water Stream is lean in said alcohols. In general, the temperatureinside said second separating means should be from about 50° C. to about150° C. and the pressure should be from about 10 psig to about 100 psig.Currently, the preferred temperatures are from 75° C. to 125° C. and thepreferred pressures are from 15 psig to 45 psig.

Said Second Water Stream is contacted with a First Steam Stream, orFirst Fuel Gas Stream in a fourth contacting means that provides afourth contacting zone where said Second Water Stream can come intocontact with said First Steam Stream, or said First Fuel Gas Stream. Anexample of said fourth contacting means is a extractor. This is thesecond nitrile-removal step. This contacting takes place underconditions that produce said First Water Stream and a First NitrileStream, from said Second Water Stream and said First Steam Stream, orsaid First Fuel Gas Stream, where said First Water Stream comprises saidwater and said First Nitrile Stream comprises said nitriles, and wheresaid First Water Stream is lean in said nitriles and said First NitrileStream is rich in said nitriles. In general, the temperature inside saidfourth contacting means should be from about 20° C. to about 150° C. andthe pressure should be from about 50 psig to about 400 psig. Currently,the preferred temperatures are from 50° C. to 70° C. and the preferredpressures are from 100 psig to 200 psig.

Said First Water Stream exits said fourth contacting means and enterssaid first contacting means.

Said First Nitrile Stream exits said fourth contacting means and entersa nitrile-collection point.

The FIGURE is a diagrammatic representation of a preferred embodiment ofan Etherification Structure that is useful in performing a preferredembodiment of the process of the invention. The following is a moredetailed discussion of said FIGURE.

Said Etherification Structure 1 comprises a First Section 10, a SecondSection 20, a Third Section 30, a Fourth Section 40, a Fifth Section 50,a Sixth Section 60, and a Seventh Section 70.

Said First Section, which is the first nitrile-removal stage, comprisesa First Vessel 100, a First Conduit 110, a Second Conduit 120, a ThirdConduit 130, and a Fourth Conduit 140. Said First Conduit 110 hasConnecting Ends 110a and 110b. Said Second Conduit 120 has ConnectingEnds 120a and 120b. Said Third Cconduit 130 has Connecting Ends 130a and130b. Said Fourth Conduit 140 has Connecting Ends 140a and 140b.

Said Second Section, which is the first ether-production stage,comprises a Second Vessel 200, a Fifth Conduit 210, a Sixth Conduit 220,a Seventh Conduit 230, an Eighth Conduit 240, and a Ninth Conduit 250.Said Fifth Conduit 210 has Connecting Ends 210a and 210b. Said SixthConduit 220 has Connecting Ends 220a and 220b. Said Seventh Conduit 230has Connecting Ends 230a and 230b. Said Eighth Conduit 240 hasConnecting Ends 240a and 240b. Said Ninth Conduit 250 has ConnectingEnds 250a and 250b.

Said Third Section, which is the second ether-production stage,comprises a Third Vessel 300, and a Tenth Conduit 310. Said TenthConduit 310 has Connecting Ends 310a and 310b.

Said Fourth Section, which is the ether-removal stage, comprises aFourth Vessel 400, an Eleventh Conduit 410, and a Twelfth Conduit 420.Said Eleventh Conduit 410 has Connecting Ends 410a and 410b. SaidTwelfth Conduit 420 has Connecting Ends 420a and 420b.

Said Fifth Section, which is the isoolefin/nonreactive-compound-removalstage, comprises a Fifth Vessel 500, a Thirteenth Conduit 510, and aFourteenth Conduit 520. Said Thirteenth Conduit 510 has Connecting Ends510a and 510b. Said Fourteenth Conduit 520 has Connecting Ends 520a and520b.

Said Sixth Section, which is the alcohol removal stage, comprises aSixth Vessel 600 and a Fifteenth Conduit 610. Said Fifteenth Conduit 610has Connecting Ends 610a and 610b.

Said Seventh Section, which is the second nitrile-removal stage,comprises a Seventh Vessel 700, a Sixteenth Conduit 710, a SeventeenthConduit 720, an Eighteenth Conduit 730, and a Nineteenth Conduit 740.Said Sixteenth Conduit 710 has Connecting Ends 710a and 710b. SaidSeventeenth Conduit 720 has Connecting Ends 720a and 720b. SaidEighteenth Conduit 730 has Connecting Ends 730a and 730b. SaidNineteenth Conduit 740 has Connecting Ends 740a and 740b.

Said Connecting End 110a is connected in fluid-flow communication withan isoolefin source, which is not depicted. Said Connecting End 110b isconnected in fluid-flow communication with said First Vessel 100. SaidConnecting End 120a is connected in fluid-flow communication with saidFirst Vessel 100. Said Connecting End 120b is connected in fluid-flowcommunication with said Connecting Ends 710b and 720b. Said ConnectingEnd 130a is connected in fluid-flow communication with said First Vessel100. Said Connecting End 130b is connected in fluid-flow communicationwith said Connecting End 210a. Said Connecting End 140a is connected influid-flow communication with said First Vessel 100. Said Connecting End140b is connected in fluid-flow communication with said Seventh Vessel700.

Said Connecting End 210a is connected in fluid-flow communication withsaid Connecting Ends 130b and 230b. Said Connecting End 210b isconnected in fluid-flow communication with said Second Vessel 200. SaidConnecting End 220a is connected in fluid-flow communication with saidSecond Vessel 200. Said Connecting End 220b is connected in fluid-flowcommunication with said Third Vessel 300. Said Connecting End 230a isconnected in fluid-flow communication with said Connecting Ends 240a and250a. Said Connecting End 230b is connected in fluid-flow communicationwith said Connecting End 210a. Said Connecting End 240a is connected influid-flow communication with said Connecting End 230a. Said ConnectingEnd 240b is connected in fluid-flow communication with an alcoholsource, which is not depicted. Said Connecting End 250a is connected influid-flow communication with said Connecting End 230a. Said ConnectingEnd 250b is connected in fluid-flow communication with said Sixth Vessel600.

Said Connecting End 310a is connected in fluid-flow communication withsaid Third Vessel 300. Said Connecting End 310b is connected influid-flow communication with said Fourth Vessel 400.

Said Connecting End 410a is connected in fluid-flow communication withsaid Fourth Vessel 400. Said Connecting End 410b is connected influid-flow communication with said Fifth Vessel 500. Said Connecting End420a is connected in fluid-flow communication with said Fourth Vessel400. Said Connecting End 420b is connected in fluid-flow communicationwith an ether-collection point, which is not depicted.

Said Connecting End 510a is connected in fluid-flow communication withsaid Fifth Vessel 500. Said Connecting End 510b is connected influid-flow communication with said Sixth Vessel 600. Said Connecting End520a is connected in fluid-flow communication with said Fifth Vessel500. Said Connecting End 520b is connected in fluid-flow communicationwith an isoolefin/nonreactive-compound-collection point, which is notdepicted.

Said Connecting End 610a is connected in fluid-flow communication withsaid Sixth Vessel 600. Said Connecting End 610b is connected influid-flow communication with said Fifth Vessel 500.

Said Connecting End 710a is connected in fluid-flow communication withsaid Seventh Vessel 700. Said Connecting End 710b is connected influid-flow communication with said Connecting End 120b. Said ConnectingEnd 720a is connected in fluid-flow communication with a water source,which is not depicted. Said Connecting End 720b is connected influid-flow communication with said Connecting End 120b. Said ConnectingEnd 730a is connected in fluid-flow communication with a steam, orfuel-gas, source, which is not depicted. Said Connecting End 730b isconnected in fluid-flow communication with said Seventh Vessel 700. SaidConnecting End 740a is connected in fluid-flow communication with saidSeventh Vessel 700. Said Connecting End 740b is connected in fluid-flowcommunication with a nitrile-collection point, which is not depicted.

A First Stream, which comprises isoolefins, nitriles, and nonreactivecompounds, originates from said isoolefin source. Said First Streamexits said isoolefin source through said Connecting End 110a and enterssaid Conduit 110. Said First Stream exits said First Conduit 110 throughsaid Connecting End 110b and enters said First Vessel 100 which is saidfirst contacting means.

A Second Stream, which comprises water, exits said Conduit 120 throughsaid Connecting End 120a and enters said First Vessel 100.

Said First Vessel 100 is a contacting means that provides a contactingzone where said First Stream can come into contact with said SecondStream. An example of said contacting means is a wash column. Thiscontacting takes place under conditions that produce a Third Stream anda Fourth Stream from said First Stream and said Second Stream, wheresaid Third Stream comprises said isoolefins and said nonreactivecompounds, and where said Fourth Stream comprises said water and saidnitriles, and where said Third Stream is lean in said nitriles whencompared with said First Stream, and where said Fourth Stream is rich insaid nitriles when compared with said Second Stream.

Said Third Stream exits from said First Vessel 100 through saidConnecting End 130a and enters said Conduit 130. Said Third Stream exitssaid Conduit 130 through Connecting End 130b and enters said ConnectingEnd 210a.

Said Fourth Stream exits said First Vessel 100 through said ConnectingEnd 140a and enters said Conduit 140. Said Fourth Stream exits saidConduit 140 through Connecting End 140b and enters said Seventh Vessel700.

An Eighth Stream, which comprises make-up alcohols, originates from saidalcohol source. Said Eighth Stream exits said alcohol source throughsaid Connecting End 240b and enters said Conduit 240. Said Eighth Streamexits said Conduit 240 through said Connecting End 240a and enters saidConnecting End 230a.

A Ninth Stream, which comprises recycled alcohols, exits said Conduit250 through said Connecting End 250a and enters said Connecting End230a.

Said Eighth Stream and said Ninth Stream combine in said Connecting End230a to form a Seventh Stream, which comprises said alcohols. SaidSeventh Stream exits said Connecting End 230a and enters said Conduit230. Said Seventh Stream exits said Conduit 230 through said ConnectingEnd 230b and enters said Connecting End 210a.

Said Seventh Stream and said Third Stream combine in said Connecting End210a to form a Fifth Stream, which comprises said isoolefins, saidalcohols, and said nonreactive compounds, and enters said Conduit 210.Said Fifth Stream exits said Conduit 210 through said Connecting End210b and enters said Second Vessel 200 which is said second contactingmeans.

Said Conduits 130, 210, 230, and their Connecting Ends form saidIsoolefin/Alcohol contacting means.

Said Second Vessel 200 is a contacting means that provides a contactingzone where said Fifth Stream can come into contact with anacidic-ion-exchange-resin catalyst and thereby produce ethers. Anexample of said contacting means is a reactor. This contacting takesplace under conditions that produce a Sixth Stream from said FifthStream, where said Sixth Stream comprises unreacted isoolefins,unreacted alcohols, said nonreactive compounds, and said ethers.

Said Sixth Stream exits said Second Vessel 200 through Connecting End220a and enters said Conduit 220. Said Sixth Stream exits said Conduit220 through Connecting End 220b and enters said Third Vessel 300 whichis said separate contacting means.

Said Third Vessel 300 is a contacting means that provides a contactingzone where said Sixth Stream can come into contact with anacidic-ion-exchange-resin catalyst, which can be the same as, ordifferent from, the acidic-ion-exchange-resin catalyst used in saidSecond Vessel 200. An example of said contacting means is a reactor,which can be the same as, or different from, said Second Vessel 200.This contacting takes place under conditions that produce a Tenth Streamfrom said Sixth Stream, where said Tenth Stream comprises unreactedisoolefins, unreacted alcohols, said nonreactive compounds, and ethers,and where said Tenth Stream is richer in said ethers than said SixthStream. The temperatures and pressures in said Second Vessel 200 andsaid Third Vessel 300 can be the same, or different, depending on, amongother things, desired products.

Said Tenth Stream exits said Third Vessel through said Connecting End310a and enters said Conduit 310. Said Tenth Stream exits said Conduit310 through said Connecting End 310b and enters said Fourth Vessel 400which is said first separating means.

Said Fourth Vessel 400 is a separating means that provides a separatingzone where said Tenth Stream is separated into two streams where onestream is rich in said ethers and the other is lean in said ethers. Anexample of said contacting means is a fractionator. This contactingtakes place under conditions that produce an Eleventh Stream and aTwelfth Stream from said Tenth Stream, where said Eleventh Streamcomprises said unreacted isoolefins, said unreacted alcohols, and saidnonreactive compounds, and said Twelfth Stream comprises said ethers,and where said Eleventh Stream is lean in said ethers and said TwelfthStream is rich in said ethers.

Said Eleventh Stream exits said Fourth Vessel 400 through saidConnecting End 410a and enters said Conduit 410. Said Eleventh Streamexits said Conduit 410 through said Connecting End 410b and enters saidFifth Vessel 500 which is said third contacting means.

Said Twelfth Stream exits said Fourth Vessel 400 through said ConnectingEnd 420a and enters said Conduit 420. Said Twelfth Stream exits saidConduit 420 through said Connecting End 420b and enters saidether-collection point.

Said Fifth Vessel 500 is a contacting means that provides a contactingzone where said Eleventh Stream can come into contact with a FifteenthStream, which comprises water. An example of said contacting means is anextractor. This contacting takes place under conditions that produce aThirteenth Stream and a Fourteenth Stream from said Eleventh Stream andsaid Fifteenth Stream, where said Fourteenth Stream comprises saidunreacted isoolefins and said nonreactive compounds, and where saidThirteenth Stream comprises said unreacted alcohols and said water.

Said Thirteenth Stream exits said Fifth Vessel 500 through saidConnecting End 510a and enters said Conduit 510. Said Thirteenth Streamexits said Conduit 510 through said Connecting End 510b and enters saidSixth Vessel 600 which is said second separating means.

Said Fourteenth Stream exits said Fifth Vessel 500 through saidConnecting End 520a and enters said Conduit 520. Said Fourteenth Streamexits said Conduit 520 through said Connecting End 520b and enters saidnonreactive-compound-collection point.

Said Sixth Vessel 600 is a second separating means that provides asecond separating zone where said Thirteenth Stream is separated intotwo streams where one stream is rich in said alcohols and the other islean in said alcohols. An example of said contacting means is afractionator. This contacting takes place under conditions that producesaid Fifteenth Stream and said Ninth Stream from said Thirteenth Stream,where said Fifteenth Stream comprises said water, and said Ninth Streamcomprises said alcohols, and where said Fifteenth Stream is lean in saidalcohols and said Ninth Stream is rich in said alcohols.

Said Fifteenth Stream exits said Sixth Vessel 600 through saidConnecting End 610a and enters said Conduit 610. Said Fifteenth Streamexits said Conduit 610 through said Connecting End 610b and enters saidFifth Vessel 500.

Said Sixteenth Stream, which comprises water, exits said Seventh Vessel700 through said Connecting End 710a and enters said Conduit 710. SaidSixteenth Stream exits said Conduit 710 through said Connecting End 710band enters said Connecting End 120b.

Said Seventeenth Stream exits said water source through said ConnectingEnd 720a and enters said Conduit 720. Said Seventeenth Stream exits saidConduit 720 through said Connecting End 720b and enters said ConnectingEnd 120b.

Said Sixteenth Stream and said Seventeenth Stream combine in saidConnecting End 120b to form said Second Stream, which comprises saidwater. Said Second Stream exits said Connecting End 120b and enters saidConduit 120. Said Second Stream exits said Conduit 120 through saidConnecting End 120a and enters said First Vessel 100.

Said Eighteenth Stream, which comprises steam, or fuel-gas, originatesfrom said steam, or said fuel gas, source. Said Eighteenth Stream exitssaid steam, or said fuel gas, source through said Connecting End 730aand enters said Conduit 730. Said Eighteenth Stream exits said Conduit730 through said Connecting End 730b and enters said Seventh Vessel 700,which is said fourth contacting means.

Said Seventh Vessel 700 is a contacting means that provides a contactingzone where said Eighteenth Stream can come into contact with said FourthStream. An example of said contacting means is a extractor. Thiscontacting takes place under conditions that produce said SixteenthStream and said Nineteenth Stream from said Eighteenth Stream, wheresaid Sixteenth Stream comprises said water.

Said Nineteenth Stream exits said Seventh Vessel 700 through saidConnecting End 740a and enters said Conduit 740. Said Nineteenth Streamexits said Conduit 740 through said Connecting End 740b and enters saidnitrile-collection point.

CALCULATED EXAMPLE

This calculated example is provide to further assist those skilled inthe art with understanding this invention.

A material balance based on certain streams in the FIGURE is tabulatedin Table One.

                                      TABLE I                                     __________________________________________________________________________              Conduit 110                                                                         Conduit 130                                                                         Conduit 720                                                                         Conduit 730                                                                         Conduit 740                                 __________________________________________________________________________    Temp °F.                                                                         100.2589                                                                            100.0000                                                                            100.0000                                                                            281.0987                                                                            100.0000                                    Pressure psia                                                                           100.0000                                                                            100.0000                                                                            15.0000                                                                             50.0000                                                                             15.0000                                     Enth MMBtu/hr                                                                           -50.296                                                                             -50.043                                                                             -6.995                                                                              -65.899                                                                             -62.829                                     Vapor Mole Fraction                                                                     0.00000                                                                             0.00000                                                                             0.00000                                                                             0.00100000                                                                          0.000174768                                 Total lb mol/hr                                                                         941.0789                                                                            939.0842                                                                            57.1139                                                                             553.2468                                                                            512.8185                                    Total lb/hr                                                                             66806.9219                                                                          66778.3125                                                                          1028.9072                                                                           9966.7412                                                                           9245.7461                                   Total std L gpm                                                                         209.1954                                                                            209.1479                                                                            2.0571                                                                              19.9265                                                                             18.4948                                     Total std V scfh                                                                        357119.31                                                                           356362.41                                                                           21673.51                                                                            209945.34                                                                           194603.66                                   Isoamylenes.sup.1                                                                       15098.385                                                                           15099.998                                                                           0.0000                                                                              0.0000                                                                              1.6116                                      Water.sup.1                                                                             38.8572                                                                             0.0000                                                                              1028.9072                                                                           9966.7412                                                                           9235.5020                                   I-Pentane.sup.1                                                                         14999.2354                                                                          15000.0000                                                                          0.0000                                                                              0.0000                                                                              0.7656                                      N-Pentane.sup.1                                                                         24998.4980                                                                          24999.9980                                                                          0.0000                                                                              0.0000                                                                              1.5001                                      1-Pentane.sup.1                                                                         10997.9023                                                                          11000.0000                                                                          0.0000                                                                              0.0000                                                                              2.0974                                      Acetonitrile.sup.1                                                                      0.0000                                                                              0.0000                                                                              0.0000                                                                              0.0000                                                                              0.0000                                      1,3-Butadiene.sup.1                                                                     673.6742                                                                            674.9437                                                                            0.0000                                                                              0.0000                                                                              1.2695                                      Propionitrile.sup.1                                                                     0.3743                                                                              3.3747                                                                              0.0000                                                                              0.0000                                                                              3.0003                                      __________________________________________________________________________     .sup.1 Flowrates in lb/hr                                                

The calculated results in Table One show that a substantial amount ofthe nitrile compounds can be removed from the etherification structurebefore they can come into contact with an acidic-ion-exchange-resincatalyst.

While this invention has been described in considerable detail withcertain preferred embodiments stated, the appended claims should not beconstrued as limited to only the preferred embodiments, but should beconsidered in light of the entire specification.

That which is claimed:
 1. An etherification process that resistsdeactivation, by nitriles, of its acidic-ion-exchange-resin catalyst,said process comprising:(a) contacting a First Isoolefin Stream, whichcomprises isoolefins, nitriles, and nonreactive compounds, with a FirstWater Stream, which comprises water, in a first contacting means underconditions that produce a Second Isoolefin Stream and a Second WaterStream from said First Isoolefin Stream and said First Water Stream,where said Second Isoolefin Stream comprises said isoolefins and saidnonreactive compounds, and where said Second Water Stream comprises saidwater and said nitriles, and where said Second Isoolefin Stream is leanin said nitriles when compared with said First Isoolefin Stream, andwhere said Second Water Stream is rich in said nitriles when comparedwith said First Water Stream; (b) contacting said Second IsoolefinStream with a First Alcohol Stream, which comprises alcohols, in anIsoolefin/Alcohol contacting zone where said Second Isoolefin Stream cancome into contact with said First Alcohol Stream, to form a FirstIsoolefin/Alcohol Stream that comprises said isoolefins, saidnonreactive compounds, and said alcohols; (c) contacting said FirstIsoolefin/Alcohol Stream with an acidic-ion-exchange-resin catalyst, ina second contacting zone under conditions that produce a First EtherStream from said First Isoolefin/Alcohol Stream, where said First EtherStream comprises unreacted isoolefins, unreacted alcohols, saidnonreactive compounds, and ethers; (d) separating said First EtherStream in a first separating zone under conditions that produce a SecondIsoolefin/Alcohol Stream and a Second Ether Stream from said First EtherStream, where said Second Isoolefin/Alcohol Stream comprises saidunreacted isoolefins, said unreacted alcohols, and said nonreactivecompounds, and said Second Ether Stream comprises said ethers, and wheresaid Second Isoolefin/Alcohol Stream is lean in said ethers and saidSecond Ether Stream is rich in said ethers; (e) contacting said SecondIsoolefin/Alcohol Stream with a Third Water Stream in a third contactingzone under conditions that produce a First Alcohol/Water Stream and aThird Isoolefin Stream from said Second Isoolefin/Alcohol Stream andsaid Third Water Stream, where said Third Isoolefin Stream comprisessaid unreacted isoolefins and said nonreactive compounds, and where saidFirst Alcohol/Water Stream comprises said unreacted alcohols and saidwater; (f) separating said First Alcohol/Water Stream in a secondseparating zone where said First Alcohol/Water Stream is separated underconditions that produce said Third Water Stream and said First AlcoholStream from said First Alcohol/Water Stream, where said First AlcoholStream comprises said unreacted alcohols, and said Third Water Streamcomprises water, and where said First Alcohol Stream is rich in saidalcohols and said Third Water Stream is lean in said alcohols; (g)contacting said Second Water Stream with a First Steam Stream in afourth contacting zone under conditions that produce said First WaterStream and a First Nitrile Stream, from said Second Water Stream andsaid First Steam Stream where said First Water Stream comprises saidwater and said First Nitrile Stream comprises said nitriles, and wheresaid First Water Stream is lean in said nitriles and said First NitrileStream is rich in said nitriles.
 2. A process according to claim 1wherein said isoolefin is selected from the group consisting ofisobutylene, isoamylene, isohexylene, isoheptylene, isooctylene,isononylene, isodecylene, isoundecylene, isododecylene, isotridecylene,isotetradecylene, isopentadecylene, isohexadecylene and mixtures of twoor more of said isoolefins.
 3. A process according to claim 1 whereinsaid alcohol is selected from the group consisting of methanol, ethanol,propanol, isopropanol, butanol, secondary butanol, pentanol, hexanol,ethylene glycol, propylene glycol, butylene glycol, glycerol, andmixtures of two or more of said alcohols.
 4. A process according toclaim 1 wherein said isoolefin is selected from the group consisting ofisobutylene and the isoamylenes and said alcohol is selected from thegroup consisting of methanol and ethanol.
 5. A process according toclaim 1 wherein said acidic-ion-exchange-resin catalyst is selected fromthe group consisting of sulfonated coals, sulfonated resins, andmixtures thereof.
 6. A process according to claim 1 wherein saidacidic-ion-exchange-resin catalyst is a sulfonated coal.
 7. A processaccording to claim 1 wherein said acidic-ion-exchange-resin catalyst isa sulfonated resin.
 8. A process according to claim 1 wherein saidacidic-ion-exchange-resin catalyst is a sulfonated polystyrene resin. 9.An etherification process that resists deactivation, by nitriles, of itsacidic-ion-exchange-resin catalyst, said process comprising:(a)contacting a First Isoolefin Stream, which comprises isoolefins,nitriles, and nonreactive compounds, with a First Water Stream, whichcomprises water, in a first contacting means under conditions thatproduce a Second Isoolefin Stream and a Second Water Stream from saidFirst Isoolefin Stream and said First Water Stream, where said SecondIsoolefin Stream comprises said isoolefins and said nonreactivecompounds, and where said Second Water Stream comprises said water andsaid nitriles, and where said Second Isoolefin Stream is lean in saidnitriles when compared with said First Isoolefin Stream, and where saidSecond Water Stream is rich in said nitriles when compared with saidFirst Water Stream; (b) contacting said Second Isoolefin Stream with aFirst Alcohol Stream, which comprises alcohols, in an Isoolefin/Alcoholcontacting zone where said Second Isoolefin Stream can come into contactwith said First Alcohol Stream, to form a First Isoolefin/Alcohol Streamthat comprises said isoolefins, said nonreactive compounds, and saidalcohols; (c) contacting said First Isoolefin/Alcohol Stream with anacidic-ion-exchange-resin catalyst, in a second contacting zone underconditions that produce a First Ether Stream from said FirstIsoolefin/Alcohol Stream, where said First Ether Stream comprisesunreacted isoolefins, unreacted alcohols, said nonreactive compounds,and ethers; (d) separating said First Ether Stream in a first separatingzone under conditions that produce a Second Isoolefin/Alcohol Stream anda Second Ether Stream from said First Ether Stream, where said SecondIsoolefin/Alcohol Stream comprises said unreacted isoolefins, saidunreacted alcohols, and said nonreactive compounds, and said SecondEther Stream comprises said ethers, and where said SecondIsoolefin/Alcohol Stream is lean in said ethers and said Second EtherStream is rich in said ethers; (e) contacting said SecondIsoolefin/Alcohol Stream with a Third Water Stream in a third contactingzone under conditions that produce a First Alcohol/Water Stream and aThird Isoolefin Stream from said Second Isoolefin/Alcohol Stream andsaid Third Water Stream, where said Third Isoolefin Stream comprisessaid unreacted isoolefins and said nonreactive compounds, and where saidFirst Alcohol/Water Stream comprises said unreacted alcohols and saidwater; (f) separating said First Alcohol/Water Stream in a secondseparating zone where said First Alcohol/Water Stream is separated underconditions that produce said Third Water Stream and said First AlcoholStream from said First Alcohol/Water Stream, where said First AlcoholStream comprises said unreacted alcohols, and said Third Water Streamcomprises water, and where said First Alcohol Stream is rich in saidalcohols and said Third Water Stream is lean in said alcohols; (g)contacting said Second Water Stream with a First Fuel Gas Stream in afourth contacting zone under conditions that produce said First WaterStream and a First Nitrile Stream, from said Second Water Stream andsaid First Fuel Gas Stream where said First Water Stream comprises saidwater and said First Nitrile Stream comprises said nitriles, and wheresaid First Water Stream is lean in said nitriles and said First NitrileStream is rich in said nitriles.
 10. A process according to claim 9wherein said isoolefin is selected from the group consisting ofisobutylene, isoamylene, isohexylene, isoheptylene, isooctylene,isononylene, isodecylene, isoundecylene, isododecylene, isotridecylene,isotetradecylene, isopentadecylene, isohexadecylene and mixtures of twoor more of said isoolefins.
 11. A process according to claim 9 whereinsaid alcohol is selected from the group consisting of methanol, ethanol,propanol, isopropanol, butanol, secondary butanol, pentanol, hexanol,ethylene glycol, propylene glycol, butylene glycol, glycerol, andmixtures of two or more of said alcohols.
 12. A process according toclaim 9 wherein said isoolefin is selected from the group consisting ofisobutylene and the isoamylenes and said alcohol is selected from thegroup consisting of methanol and ethanol.
 13. A process according toclaim 9 wherein said acidic-ion-exchange-resin catalyst is selected fromthe group consisting of sulfonated coals, sulfonated resins, andmixtures thereof.
 14. A process according to claim 9 wherein saidacidic-ion-exchange-resin catalyst is a sulfonated coal.
 15. A processaccording to claim 9 wherein said acidic-ion-exchange-resin catalyst isa sulfonated resin.
 16. A process according to claim 9 wherein saidacidic-ion-exchange-resin catalyst is a sulfonated polystyrene resin.17. A process comprising:(a) contacting a First Isoolefin Stream, whichcomprises isoolefins, nitriles, and nonreactive compounds, with a FirstWater Stream, which comprises water, in a first contacting means underconditions that produce a Second Isoolefin Stream and a Second WaterStream from said First Isoolefin Stream and said First Water Stream,where said Second Isoolefin Stream comprises said isoolefins and saidnonreactive compounds, and where said Second Water Stream comprises saidwater and said nitriles, and where said Second Isoolefin Stream is leanin said nitriles when compared with said First Isoolefin Stream, andwhere said Second Water Stream is rich in said nitriles when comparedwith said First Water Stream; (b) contacting said Second Water Streamwith a First Steam Stream, or a First Fuel Gas Stream, in a contactingzone under conditions that produce a First Nitrile Steam, from saidSecond Water Stream and said First Steam Stream, or said First Fuel GasStream, where said First Nitrile Stream comprises said nitriles.